p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 615

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Figure 22.3 shows an example in which a transition is made to software standby mode at the
falling edge of the NMI pin, and software standby mode is cleared at the rising edge of the NMI
pin.
In this example, an NMI interrupt is accepted with the NMIEG bit in SYSCR cleared to 0 (falling
edge specification), then the NMIEG bit is set to 1 (rising edge specification), the SSBY bit is set
to 1, and a SLEEP instruction is executed, causing a transition to software standby mode.
Software standby mode is then cleared at the rising edge of the NMI pin.
Oscillator
φ
NMI
NMIEG
SSBY
Figure 22.3 Software Standby Mode Application Example
NMI exception
handling
NMIEG = 1
SSBY = 1
SLEEP instruction
Software standby mode
(power-down mode)
Rev. 1.00 Sep. 21, 2006 Page 577 of 658
stabilization
Oscillation
time t
Section 22 Power-Down Modes
OSC2
NMI exception
handling
REJ09B0310-0100